**3. Results and discussion**

### **3.1 General must and wine composition**

General composition of must obtained with the two skin-contact treatment and conventional way from cv. Malvasia *aromatica* are given in **Table 1**. In the skincontact treatment assays, the total acidity of the must decreases along with a slight increase in pH. This is due to the transfer of cations from the skin to the must during the previous maceration stage, and results in a decrease of acidity in the form of potassium bitartrate together with a salification of the acids [18]. The results show an increase in Yeast assimilable nitrogen (YAN) according to the time of contact with the skin, being more notable with M18; M6 did not cause variations in YAN content. These results are in agreement with the studies carried out by other authors, where a period of contact with the skin favors the enrichment of the musts in terms of amino acid content [19, 20]. In general, the effect of skin-contact in both assays is not very pronounced, which could be related to the low temperature


*b Yeast assimilable nitrogen (YAN).*

#### **Table 1.**

*General composition of must obtained with different treatment: Conventional (C) and skin-contact treatment: Assay 1 (A1), 18 h (M18) and assay 2 (A2), 6 h (M6).*

*Influence of Skin-Contact Treatment on Aroma Profile of Malvasia* Aromatica *Wines… DOI: http://dx.doi.org/10.5772/intechopen.99216*

(10°C) and the time of contact, compared to other studies on white varieties (15.5°C, 20°C and 24°C [21]).
